3. Statistical Anayses
4. Outcomes
RESULTS
1. Population characteristics
2. Events
3. Sub-group analysis according to the time of new onset atrial fibrillation 4. Analysis of events at one year on the population of the RIMA registry DISCUSSION
1. Limits
CONCLUSION
BIBLIOGRAPHY
FIGURES
TABLES
TABLE OF CONTENTS
ABSTRACT
Aims : New onset atrial fibrillation after a STEMI is at greater risk of complications. We focus on determining the incidence of new onset AF, analysing the prevalence of prior AF for patients hospitalized for STEMI, identifying predictive factors of AF and assessing the impact of AF on morbidity and mortality during hospitalization and at one year.
Methods : 3357 patients with STEMI were enrolled in the RIMA and ORBI registries. They were divided into 3 groups according to the timing of AF occurrence: 1) patients free of AF; 2) patients with prior AF; 3) patients with New Onset AF. We defined 3 primary outcomes during hospitalization and at 1-year post-discharge: mortality, heart failure (HF) and stroke. One-year events were only assessed on RIMA registry.
Results : During hospitalization, cardiovascular mortality was higher in prior AF (10.7%) and new onset AF (7.5%) compared to AF-free (3.2%). Results were similar for heart failure with respectively 25.9%, 27.0% and 8.6%. Strokes were more frequent in new onset AF versus AF-free patients (3,2%
versus 0,4%, p < 0.001). In multivariate analysis, NOAF was an independent factor in development of heart failure during hospitalization (p 0.001, OR 1.897 [1.303-2.763]) and also in development of stroke (p 0.006, OR 4.304 [1.522-12.168]). At one year, from RIMA registry, we observed a significant difference in mortality, stroke and hospitalization for heart failure between AF-free and new onset AF patients. Mortality was 28.9% for NOAF group versus 8.2% in AF-free group (p <
0.001) and stroke rate was 5.9% versus 1.12% (p 0.007). In NOAF, 9.6% of patients were hospitalized within one year for heart failure versus 3% in AF-free group (p<0.001).
In multivariate analysis, absence of AF appears to be a protective factor for the occurrence of stroke (p 0.033 OR 0.267; CI [0.080-0.898]) and heart failure (p 0.030 OR 0.398; CI [0.173-0.915]).
Conclusion : NOAF occurring after STEMI is a marker of severity that should not be overlooked. AF is an independent marker for stroke and heart failure during hospitalization and a marker for mortality, readmission for heart failure and stroke at one year.
INTRODUCTION
Atrial fibrillation (AF) is the most common supraventricular rhythm disorder, with an incidence ranging from 5% to 18% for patients with myocardial infarction, although there has been an improvement these last years with an incidence of 4.8% to 7.7% (1) since early revascularization became widespread.
The occurrence of AF in STEMI is due to different mechanisms. Ischemia reduces atrial perfusion, increases the telediastolic pressure of the left ventricle as well as the pressure in the left atrium, leads to diastolic dysfunction and autonomic nervous system abnormalities promoting this arrhythmia. The inflammation induced by ischemia also causes rhythm disturbance (2).
It has already been shown that patients who present AF after STEMI have more co-morbidities and are at greater risk of complications (3)(4), including increased mortality, suggesting that atrial fibrillation should be considered as a true marker of severity (5).
Furthermore, it has also been shown that depending on the time of onset of AF in the post-infarction period, the impact on morbidity and mortality was different. Indeed, some studies have demonstrated a higher morbidity and mortality for AF occurring more than 30 days after STEMI (6).
In this study, we focus on evaluating the incidence of New Onset Atrial Fibrillation (NOAF), the prevalence of prior AF for patients hospitalized for STEMI, identifying predictive factors of AF and the impact of AF on morbidity and mortality during hospitalization and at one year.
We also analyzed intra-hospital morbidity and mortality according to the time of AF occurrence: early (< 24h), intermediate (24-72h) or late (>72h).
METHODS
This is a retrospective study based on the prospective registries RIMA (Registre des Infarctus en Maine-Anjou) and ORBI (Observatoire Régional Breton sur l'Infarctus).
The RIMA Registry prospectively included all patients presenting for STEMI and treated at the Angers University Hospital and who could also come from three peripheral centers that do not perform angioplasty (Cholet, Saumur and Château-Gontier Hospital Centers).
The ORBI registry prospectively included all patients presenting for STEMI within 24 hours of the onset of symptoms in the 9 Breton interventional cardiology centers (Rennes University Hospital; Clinique Saint-Laurent, Rennes; Saint-Malo Hospital; Saint-Brieuc Hospital; Lorient Hospital; Vannes Hospital; Brest University Hospital; Quimper Hospital; Clinique du Grand Large, Brest).
We study here the period from January 2017 to December 2018 for the ORBI registry and from January 2016 to July 2019 for the RIMA registry.
1. Diagnosis of atrial fibrillation and myocardial infarction
Atrial fibrillation is defined by the absence of distinct P waves and an irregular R-R interval on the ECG.
All patients were monitored during the intensive care hospitalization. A 12-lead ECG was performed whenever an atrial fibrillation was suspected on the monitoring.
Patients were classified into three groups: 1) No AF; 2) Patients with a history of AF (permanent, paroxysmal, or persistent); 3) Patients with New Onset AF between the first medical contact for STEMI and discharge.
For this last group, subgroups were carried out according to the time of onset of AF:
early AF occurring within the first 24 hours of hospitalization, intermediate AF occurring
between 24 and 72 hours of hospitalization and late AF occurring more than 72 hours after STEMI.
STEMI was defined by the following characteristics: ST segment elevation ≥0.1 mV in two contiguous peripheral leads, and V5 V6, or > 0.2mV in two contiguous leads from V1 to V4 associated with troponin elevation.